1. Field of the Invention
The present invention relates to an audio signal processor for performing a signal processing on two audio signals in correspondence with an external operation to produce an output.
2. Description of the Related Art
In a musical performance in a discotheque or a nightclub, a so-called DJ (disc jockey) plays a role in skillfully operating a plurality of record players and a sound mixer to join or mix sequential pieces of music with each other, thus producing musical sounds suitable for a dance. In the past, the DJ's operation has been carried out exclusively with the use of analogue records. Decrease in availability of such analogue records leads to the needs for carrying out the above-described DJ's operation utilizing compact discs, which are widely available. Thus, attention has been directed to a CD player capable of externally controlling functions of reproduction, pause and the like and operational conditions including a reproduction speed in response to the DJ's operation (hereinafter referred to as the “DJ-compatible CD player”). If such a DJ-compatible CD player is used in combination with a mixer for the DJ's operation, the availability thereof is enhanced so that it becomes useful to a professional DJ, as well as enables a DJ hobbyist to easily enjoy the DJ's operation.
Typically, in the DJ's operation utilizing the above-described DJ-compatible CD player in combination with the mixer, when a number being reproduced is to be joined to the next number, a reproduction speed and a reproduction position are previously adjusted, and then at a predetermined timing, the number being reproduced is joined to the next number through cross-fading with the mixer. In order to perform such an operation, the mixer is provided with a cross-fader that outputs two numbers in a mixed state at a predetermined ratio according to a position of the operation device.
When the two numbers are joined to each another with the use of such a cross-fader, a user may wish not only to adjust a volume, but also to add certain effects to the number for an enhanced performance effect. For example, when joining the two numbers to each another, the number being reproduced may be joined to the next number by gradually reducing the volume thereof while adding an echo effect to a predetermined part thereof. However, in order to implement such an operation, it is required to simultaneously perform the operations of varying the volume with the use of the cross-fader and of adding an effect, such as echo, to the number. This is highly difficult and burdensome for a DJ. Besides, distracted by such a complicated operation, the basic operation of joining the two numbers may be failed.
Therefore, in view of these problems, an object of the present invention is to provide an audio signal processor capable of realizing the operation of joining two numbers by adding an effect corresponding to a DJ's operation to an audio signal and the DJ's operation with an enhanced operability and functionality.